Patrick made the apparent reference to so-called birthers during an interview on WCVB-TV. Birthers maintain President Barack Obama was born in Kenya despite the fact that Hawaii officials have repeatedly verified Obama's U.S. citizenship.

Asked whether Brown's ads are good political strategy, the Democratic governor said he hoped not and added that "Sen. Brown has turned into a Bay State birther."

The ads suggest Warren used the claims to get hired as a Harvard Law School professor, something she's denied.

Warren has said she was told growing up her mother had Native American heritage.